﻿/* Copyright 2010-present MongoDB Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

using System;

namespace MongoDB.Driver.Linq.Linq3Implementation.Ast.Expressions
{
    internal enum AstNullaryWindowOperator
    {
        Count,
        DenseRank,
        DocumentNumber,
        Rank
    }

    internal static class AstNullaryWindowOperatorExtensions
    {
        public static string Render(this AstNullaryWindowOperator @operator)
        {
            return @operator switch
            {
                AstNullaryWindowOperator.Count => "$count",
                AstNullaryWindowOperator.DenseRank => "$denseRank",
                AstNullaryWindowOperator.DocumentNumber => "$documentNumber",
                AstNullaryWindowOperator.Rank => "$rank",
                _ => throw new InvalidOperationException($"Unexpected nullary window operator: {@operator}.")
            };
        }
    }
}
